Method validate

/**
 * Method to validate form data.
 *
 * Validation warnings will be pushed into JForm::errors and should be
 * retrieved with JForm::getErrors() when validate returns boolean false.
 *
 * @param   array   $data   An array of field values to validate.
 * @param   string  $group  The optional dot-separated form group path on which to filter the
 *                          fields to be validated.
 *
 * @return  boolean  True on success.
 *
 * @since   1.7.0
 */
public function validate($data, $group = null)
{
    // Make sure there is a valid Form XML document.
    if (!$this->xml instanceof \SimpleXMLElement) {
        throw new \UnexpectedValueException(sprintf('%s::%s `xml` is not an instance of SimpleXMLElement', \get_class($this), __METHOD__));
    }
    $return = true;
    // Create an input registry object from the data to validate.
    $input = new Registry($data);
    // Get the fields for which to validate the data.
    $fields = $this->findFieldsByGroup($group);
    if (!$fields) {
        // PANIC!
        return false;
    }
    // Validate the fields.
    foreach ($fields as $field) {
        $name = (string) $field['name'];
        // Define field name for messages
        if ($field['label']) {
            $fieldLabel = $field['label'];
            // Try to translate label if not set to false
            $translate = (string) $field['translateLabel'];
            if (!($translate === 'false' || $translate === 'off' || $translate === '0')) {
                $fieldLabel = Text::_($fieldLabel);
            }
        } else {
            $fieldLabel = Text::_($name);
        }
        $disabled = (string) $field['disabled'] === 'true' || (string) $field['disabled'] === 'disabled';
        $fieldExistsInRequestData = $input->exists($name) || $input->exists($group . '.' . $name);
        // If the field is disabled but it is passed in the request this is invalid as disabled fields are not added to the request
        if ($disabled && $fieldExistsInRequestData) {
            throw new \RuntimeException(Text::sprintf('JLIB_FORM_VALIDATE_FIELD_INVALID', $fieldLabel));
        }
        // Get the field groups for the element.
        $attrs = $field->xpath('ancestor::fields[@name]/@name');
        $groups = array_map('strval', $attrs ?: []);
        $attrGroup = implode('.', $groups);
        $key = $attrGroup ? $attrGroup . '.' . $name : $name;
        $fieldObj = $this->loadField($field, $attrGroup);
        if ($fieldObj) {
            $valid = $fieldObj->validate($input->get($key), $attrGroup, $input);
            // Check for an error.
            if ($valid instanceof \Exception) {
                $this->errors[] = $valid;
                $return = false;
            }
        } elseif (!$fieldObj && $input->exists($key)) {
            // The field returned false from setup and shouldn't be included in the page body - yet we received
            // a value for it. This is probably some sort of injection attack and should be rejected
            $this->errors[] = new \RuntimeException(Text::sprintf('JLIB_FORM_VALIDATE_FIELD_INVALID', $key));
        }
    }
    return $return;
}